Do any programs require 4 LORs?
None that I've found. Here are the minimum LOR requirements listed by state for just about every program that isn't Ivy League or located in California, New York City, Miami, Dallas, Chicago or Boston. Albany was the only one I saw with a maximum of 3.
Alabama At least 2
Arkansas No requirements?
Loma Linda ?
Colorado ?
U of Florida 3 letters
Medical College of Georgia 3 letters
Iowa 3 letters
Indiana 3 or 4
U of Kansas (KC) 3 letters
U of Kansas (Wichita) 3 letters, CV
U of Kentucky (Lexington) 3 letters, ERAS CV
U of Louisville 3 letters
LSU Shreveport 3 letters
Ochsner at least 3
Tulane at least 3
LSU New Orleans 3 letters
Lahey at least 3
UMMS Baystate 3 letters
U of Mass 3 letters
Maryland 2 letters
Maine 3 letters
Wayne State 3 letters
William Beaumont 3 letters
U of Michigan 3 letters
Henry Ford ?
Detroit Medical Center ?
U of Minnesota 3 letters
U of Missouri Columbia 3 letters
Washington University/ B-JH Missouri 3 letters
U of Missouri Kansas City ?
St. Louis University 3 letters
Mississippi 3 letters
U of North Carolina ?
Wake Forest 3 letters
Nebraska 3 letters
Mary Hitchcock New Hampshire 3 letters
New Mexico 3 letters
U of Rochester ?
Buffalo ?
SUNY Upstate 3 letters
Albany Medical Center Max 3, 2 must be anes
Doctors Hospital Ohio ?
Ohio State Columbus 3 letters
Cincinnati 3 letters
Case Western/Cleveland Clinic 3 letters
U of Toledo 2 letters
Case Western Metrohealth no requirement
Oklahoma no requirement
Oregon 3 letters
Geisinger Danville PA 3 letters
Penn State Hershey 3 letters
Drexel 3 letters
U of Pennsylvania ?
Thomas Jefferson 2 letters
UPMC Pittsburgh 3 letters
Temple 2 letters
Allegheny Health Pittsburgh 3 letters
South Carolina 3 letters
Tennessee Knoxville at least 3
U of Texas Galveston ?
Texas Tech Lubbock 3 letters
U of Texas San Antonio ?
Texas A&M 3 letters
Baylor minimum 3
U of Texas Houston ?
U of Utah minimum 3
U of Virginia Charlottesville 3 letters
VCU Richmond ?
Vermont at least 3
Virginia Mason Seattle minimum 3
U of Washington Seattle minimum 3
U of Wisconsin Madison ?
Medical College of Wisconsin Milwaukee 3 letters, 2 anes
West Virginia 3 letters